— James TobinContext: For me, growing up in the 1930s, the two motivations powerfully reinforced each other. The miserable failures of capitalist economies in the Great Depression were root causes of worldwide social and political disasters. The crisis triggered a fertile period of scientific ferment and revolution in economic theory.

— James TobinContext: A forthcoming book by Harry Markowitz, Techniques of Portfolio Selection, will treat the general problem of finding dominant sets and computing the corresponding opportunity locus, for sets of securities all of which involve risk. Markowitz's main interest is prescription of rules of rational behaviour for investors; the main concern of this paper is the implications for economic theory, mainly comparative statics, that can be derived from assuming that investors do in fact follow such rules.
Tobin, James. "[http://web.uconn.edu/ahking/Tobin58.pdf Liquidity preference as behavior towards risk]." The review of economic studies (1958): 65-86.

— James TobinContext: Keynesian economics was, in the context of those times, essentially conservative. The message was that capitalism was not doomed; its major failing, chronic large-scale unemployment, could be remedied fairly easily, by intelligent use of the fiscal and monetary instruments governments already had at their disposal. This message was not welcome news to Marxists committed to the view that the system was no longer structurally capable of prosperity and progress.
James Tobin, "A Revolution Remembered", Challenge (1988).